One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,3)(5,6)(7,10)(8,9)(11,12)(14,20)(15,25)(17,18)(22,26)(23,24)(27,28)(6,9)(10,12)(13,14,17,20,19,23,18,24)(15,16,22,27,26,21,25,28)(5,7,8,11)(6,10,9,12)(13,15,17,22,19,26,18,25)(14,21,20,28,23,16,24,27)(1,3,4,2)(13,16)(14,22)(15,24)(17,27)(18,28)(19,21)(20,26)(23,25)(14,23)(16,21)(20,24)(27,28) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.